Reuters - About 150 Afghan schoolgirls were poisoned on Tuesday after drinking contaminated water at a high school in the country's north, officials said, blaming it on conservative radicals opposed to female education.

Since the 2001 toppling of the Taliban, which banned education for women and girls, females have returned to schools, especially in Kabul.

But periodic attacks still occur against girls, teachers and their school buildings, usually in the more conservative south and east of the country, from where the Taliban insurgency draws most support.

"We are 100 percent sure that the water they drunk inside their classes was poisoned. This is either the work of those who are against girls' education or irresponsible armed individuals," said Jan Mohammad Nabizada, a spokesman for education department in northern Takhar province.

Some of the 150 girls, who suffered from headaches and vomiting, were in critical condition, while others were able to go home after treatment in hospital, the officials said. They said they knew the water had been poisoned because a larger tank used to fill the affected water jugs was not contaminated.

"This is not a natural illness. It's an intentional act to poison schoolgirls," said Haffizullah Safi, head of Takhar's public health department.

None of the officials blamed any particular group for the attack, fearing retribution from anyone named. Education for women was outlawed by the Taliban government from 1996-2001 as un-Islamic.

According to CNN today two school caretakers have been arrested. There is a video and still photographs. Some of the girls have been taken out into the fresh air which sounds sensible but, in Afghanistan they then have to wear a burka. How unpleasantly nightmarish must it be to deal with nausea and sickness under a shroud?